硫酸锰对盐碱胁迫下栽培稗幼苗光合与氮代谢的影响  

Effect of manganese sulfate on photosynthesis and nitrogen metabolism of cultivated Indian barnyard grass seedlings under saline-alkali stress

作　　者：刘昌壮 陶雨朝 李明[1] 张小明[1] LIU Chang-zhuang;TAO Yu-zhao;LI Ming;ZHANG Xiao-ming(College of Agriculture,Northeast Agricultural University,Harbin 150030,China)

机构地区：[1]东北农业大学农学院,黑龙江哈尔滨150030

出　　处：《草业学报》2024年第12期84-98,共15页Acta Prataculturae Sinica

摘　　要：土壤盐碱化降低了锰的有效性,严重影响作物的生长和产量形成,而外源补充硫酸锰改善苏打盐碱条件下作物生长的生理机制尚不清楚。本试验以栽培稗为材料,设置硫酸锰浸种(JZ)和施肥(SF)两种处理,探讨硫酸锰对盐碱胁迫下作物幼苗(V5)的生理调节作用。结果表明:栽培稗在盐碱胁迫下叶绿素含量显著减少且最大光化学效率(Fv/Fm)下降,抑制了叶绿素荧光参数在光响应曲线上的表现,导致光合效率显著降低。同时硝酸还原酶、谷氨酰胺合成酶等氮同化关键酶活性下降,硝态氮含量增加,最终引起碳氮代谢平衡失调,地上部生长受到抑制,干物质更多地分配于根部,根冠比显著增加。在施用硫酸锰肥料或浸种处理后,进一步促进了栽培稗根系的发育,提高了吸收氮素的能力,增强了氮代谢关键酶的活性,有效促进了游离氨基酸的积累,提高了植物整体氮同化效率,而且促进了叶绿素和类胡萝卜素的积累,提高了Fv/Fm及光系统的能量传递,盐碱胁迫下作物苗期光合能力得到显著提升,作物生长得到明显改善。两种处理方式相比,施肥处理更能够有效减轻盐碱胁迫对作物造成的损伤,平衡作物整体碳氮代谢能力。Soil salinization reduces plant uptake of manganese,seriously affecting the growth and yield of crops.However,it is unclear if exogenously supplied manganese sulfate can improve crop growth under soda solonetz conditions.In this experiment,two Mn supplementation treatments,manganese sulfate seed soaking and fertilization,were applied to cultivated Indian barnyard grass(Echinochloa frumentacea),to investigate the physiological response to manganese sulfate of crop seedlings at V5 growth stage under saline-alkali stress.It was found that salinealkaline stress significantly reduced the chlorophyll content and decreased the optimal/maximal quantum yield of PSⅡ(Fv/Fm)of Indian barnyard grass seedlings.This inhibition affected the performance of chlorophyll fluorescence parameters in the light response curve and led to a significant decrease in photosynthetic efficiency.Additionally the activities of key enzymes involved in nitrogen assimilation,such as nitrate reductase and glutathione synthetase decreased while the nitrate nitrogen content increased,ultimately this imbalance disrupted the carbon and nitrogen metabolism balance,inhibiting shoot growth.More dry matter was allocated to the roots,resulting in a significant increase in the root∶shoot.For saline-alkali-inhibited seedlings,application of manganese sulfate fertilizer or seed dipping treatment,promoted the development of the root system,enhancing nitrogen absorption ability,and increasing the activity of key enzymes involved in nitrogen metabolism.This led to effective accumulation of free amino acids and enhanced overall nitrogen assimilation efficiency in the plant.Additionally,manganese supplementation promoted the accumulation of chlorophyll and carotenoids,increased the Fv/Fm,and improved energy transfer within the photosystem.Consequently,the photosynthetic capacity of crop seedlings under salinity stress was significantly increased,resulting in improved crop growth.Comparing the seed soaking and fertilization treatments,fertilization was more effec

关 键 词：栽培稗 苏打盐碱土 硫酸锰 光合作用 氮同化 

分 类 号：S156.4[农业科学—土壤学] S544.9[农业科学—农业基础科学]